Vertical lead-cable press



Oct 30, 1928.

I P. WIEGHARDT VERTICAL LEAD CABLE PRESS Filed Dec. 51, 1926 Patented Oct. 30, 1928.

UNITED STATES PATENT OFFICE.

PAUL WIEGHABD'IL QF MAGDEBUBG, GERMANY, ASSIGNOR TO THE FIRM: .FRIED. KRUIPI' GRUSONWERK AKTIENGESELLSCHAFT, F. MAGDEBURG-BUCKAU, GER- MANY.

VERTICAL LEAD-CABLE PRESS.

Application filed December 31, 1926, Serial No. 158,368, and in Germany February'w, 1926.

- This invention relates to vertical lead cable presses, and more particularly to the fitting of tool holders therein. It is necessary that the press heads of Vertical lead cable presses should be made in two parts so as to be able to machine the conduits which guide the lead admitted from the top into the press head 1n such a manner that it escapes horizontally between the mandrel and the matrix in the form of a lead covering. This necessity involves the drawback that the tool holders, which hitherto have been screwed into the press head, either get their screw threads damaged owing to the division of the tapped thread in the press head, or, in their turn, damage the said tapped thread if the threads do not agree or coincide exactly. Such want of exact coincidence or agreement of the threads occurs,

according to experience, after a certain time of working, as the operation of a lead cable press results in the press head being exposed to considerable variations of temperature which in the course of time result in warping;

a change of shape of the presshead is also produced owing to the high pressure. in the interior. The warping and changes of shape,

.even though they are slight, lead, owing to the heavy stresses on the threads, to damage to the thread or even to a complete destruction of single threads, or ofthe whole of them, by

breaking. These drawbacks occur more articularly in the thread of the mandrel ho der and in the corresponding tapped thread of the press head, as the working of the press makes it necessary to force the mandrel into the leadcontained in the press head by means of the mandrel'holder, for the purpose of determining the correct thickness of wall of the lead covering.

o Accordin to this invention the above mentioned draw acks are avoided by inserting in the divided press head one or more sleeves,

each made in one piece, into which the tool' holders are screwed.

5 By way of example, the accompanying drawing shows the press head of a vertical lead cable press embodying the present invention: in the drawing v Figure 1 is a vertical section of the press head through the axis of the tool holders, and,

Figure 2 1s a plan of the bottom portion of the press head with the tool holders in section.

In the construction illustrated recesses in the two portions 1 and 2 of the press head accommodate a screw-threaded sleeve 3 provided with a collar 4, which, as indicated, may be midway of its length, and occupies an annular groove 5. The sleeve 3 is so dimensioned as to leave a slight space between its external surface other than that of the collar 4 and the recesses which accommodate it, and its rotation relatively to the press head is prevented by means of a key 6. The'mandrel holder 7 is screwed into the sleeve 3 and the matrix holder 8 could also be mounted in a. similar sleeve in one piece.

The construction of the sleeve above described, which could be modified to prevent the sleeve takes place for'instance when the v tool holders (during the changing of the.

tools) are withdrawn, and the sleeve is cooled by the surrounding air. This contraction of the sleeve is very desirable and advantageous because the dismantled tool holders are also cooled and therefore contract. When re inserting the tool holders, there is therefore a probability that the tools and the screwthreaded sleeves will have approximately the same temperature. In any case, however, the sleeve will assume, after arelatively short time, the temperature of the tool holder, as it is in thorough contact with the latter, whilst it is in contact with the press head onl by means of the relatively narrow collar 4. s equalization of temperature between the tool holder and sleeve results in all the threads of the tool holder and of the sleeve bearing in a uniform manner. This is of eat importance as the guarantee against me e to I which lie parallel to the toolholder axis, the

adapted to receive said collar, the surface of said sleeve, with the exception of said collar, being separated from the walls of said re; cesses.

The foregoing specification signed at Berlin, Germany, this 17th day of December, 1926.

PAUL WIEGHARDT. 

